This is the UK's first proton clinical trial. Published in the Clinical Oncology, this editorial provided the rational and the plan of the trial. It is a multicenter phase III trial of IMPT versus IMRT for oropharyngeal squamous cell carcinoma (OPSCC), with the primary objective to assess whether IMPT compared with IMRT reduces late treatment-related toxicities in patients with locally advanced OPSCC who require treatment with concurrent chemotherapy and bilateral neck radiotherapy.

Secondary objectives include validation of a biomarker (NTCP model) as a predictor of benefit from IMPT versus IMRT and an assessment of cost-effectiveness. TORPEdO is a flagship study and will position the UK's two NHS proton facilities as international centers for IMPT clinical research to inform evidence-based clinical practice and improve treatment outcomes for patients.